STAND ALONE AIR FLOW SENSOR

Models 0101, 5101, 5201

This compact air flow sensor is specially designed for air flow monitoring and provides early warnings of clogged filters. Its compact housing style fits easily into ventilation systems and features an adjustable potentiometer to establish a setpoint. An LED provides visual indication when flow is above or below the setpoint. This airflow sensor is based on the calorimetric principle and is an inexpensive alternative for mechanical flaps and pressure cells. All components of the airflow sensor are incorporated in a compact smooth cylindrical plastic housing. The airflow sensor has a built-in timer that serves as a switch-on delay for the fan or ventilator. During this time the output is closed, the relay is energized which is also visually displayed by means of a simultaneous lighting of a red and a green LED. The switch point can be set by means of a potentiometer and is indicated by a red or green LED. In the case of no flow the red LED lights. If the green LED does not light, the output relay is de-energized. When the airflow monitor detects flow the red LED goes out, the green one lights and the output relay is energized. The output signal is available as a floating NO contact. The length of the airflow monitor allows a maximum immersion of 120 mm into the air duct. It is installed by means of a mounting clamp which is secured to the duct via two self-tapping screws. The airflow sensor can also be used for industrial airflow monitoring, since during the design of the sensor part special emphasis was put on the protection of the PTC's against mechanical destruction by solid particles in the medium. The PTC's are included in the sensor head and are protected against mechanical damage from outside by means of flush mounted metal plates. The metal plates also provide a good heat contact to the medium.

Sigma air flow measuring blades have been designed and manufactured for use in all types of air flow systems. The flow measuring blades, when correctly placed in an air flow, generate a differential pressure, the square root of which is proportional to the air flow.

Sigma air flow measuring blades ensure accurate indication, control or recording of air flow velocity and volume.

Permit velocity measurements from 3 to 100 m/s (9 Pa to 10000 Pa).

Airfoil section limiting differential heads (<3%) and turbulences.

Distribution of the measurement apertures on the airfoil permitting the medium air flow control (average of the differential pressures).

The choice of the number of blades depends on the shape of the duct and the accuracy wished. One or several Sigma blades can be used depending on the applications.

15 standard lengths available:100/125/160/200/250/315/400/500/630/800/1000/1500/2000/2500/3000mm, with others available on request.

Air Flow Sigma Cones for measuring direct air flows in ventilators and HVAC systems
By placing a Sigma Capture Cone over a diffuser or grille, you can measure air volume in order to verify air flow distribution. The easily observed trend values and fast meter response make the Sigma Cones the preferred instrument for facility engineers.